20981232 has 30 divisors (see below), whose sum is σ = 58718712. Its totient is φ = 6993696.

The previous prime is 20981231. The next prime is 20981237. The reversal of 20981232 is 23218902.

It is a happy number.

It is a junction number, because it is equal to n+sod(n) for n = 20981196 and 20981205.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (20981231) by changing a digit.

It is a polite number, since it can be written in 5 ways as a sum of consecutive naturals, for example, 72708 + ... + 72995.

Almost surely, 2^20981232 is an apocalyptic number.

It is an amenable number.

20981232 is an abundant number, since it is smaller than the sum of its proper divisors (37737480).

It is a pseudoperfect number, because it is the sum of a subset of its proper divisors.

20981232 is a wasteful number, since it uses less digits than its factorization.

20981232 is an odious number, because the sum of its binary digits is odd.

The sum of its prime factors is 145717 (or 145708 counting only the distinct ones).

The product of its (nonzero) digits is 1728, while the sum is 27.

The square root of 20981232 is about 4580.5274805420. The cubic root of 20981232 is about 275.8102034763.

Subtracting 20981232 from its reverse (23218902), we obtain a triangular number (2237670 = T₂₁₁₅).

The spelling of 20981232 in words is "twenty million, nine hundred eighty-one thousand, two hundred thirty-two".